On the assumption you wish to take it in without paying duties, you will also have to reckon with the fact that re-entering the UK (especially from a non-EU country) at any other time, you could be faced with UK customs wanting to know where you got it from. They are rarely in a joking mood when they ask. And that would bring you back to square one. Several acquaintances of mine were picked out of the green line last year. They had UK bought gear and could produce the requested copy of their bills. So they were safe and dry.
Not declaring a camera bought abroad is indeed considered smuggling and the penalties are known to be fairly high.
Whether this system to your liking or not is obviously up to you. Whether you are ready to chance it and try to beat the system is also up to you. 
According to HM Revenue & Customs things run that way:
"You can bring in other goods [than tobacco or spirits] worth up to £390 without having to pay tax and/or duty.
If you arrive by private plane or private boat for pleasure purposes, you can only bring in other goods worth up to £270 tax and duty free.
If you bring in any single item worth more than your allowance, you must pay duty and/or tax on the full item value, not just the value above the allowance. You also cannot group individual allowances together to bring in an item worth more than the limit."
And there are most likely countless additional pages of small print to give you the minutest details, but this is certainly neither worth your time nor mine.